To purify water and to prevent odours/bacteria forming in water containers use just 1 drop per litre.
The concentration is 24,000ppm - super strength. You won't find any better.

Other Notes:
? The 100ml bottle has a dropper insert so drops can be taken directly from this bottle. The 10ml bottles are convenient for traveling or taking to work.
? The above picture shows the extra 10ml CDS in a plastic bottle. However, on posting, the 10ml will also be provided in a glass bottle.